The present invention relates to a bone-strengthening agent, a bone-strengthening food, and a bone-strengthening feed composition, which are capable of preventing a decrease in bone density accompanying the onset or progress of osteoporosis.
In Japan with an aging society, the number of senior persons who have fallen in a bedridden state because of fracture due to osteoporosis, etc., is increasing. Therefore, it is an extremely important task to prevent osteoporosis. With this as a backdrop, a number of remedies have been developed while studies on preventing osteoporosis by means of food ingredients contained in meals and health foods have been increasing. Also, it is important for increasing cost efficiency to strengthen the bone of domestic animals and poultry, thereby maintaining the soundness thereof, as in humans. On the other hand, it is said that pets require more calcium than humans do in order to make their skeletal frames stronger. Therefore, pet foods dedicated to strengthening bone have been demanded.
In contemplating strengthening bone, it is a key point to promote efficient absorption of calcium, which is a main component of bone and is necessary for maintaining bone sound.
Casein phosphopeptide (hereinafter, abbreviated as xe2x80x9cCPPxe2x80x9d) prepared from proteins in cows"" milk has an action of promoting the absorption of calcium and has been practically used as a raw material for a number of foods and feeds. Further, as the invention by which CPP is added to beverages and foods or feeds in order to exhibit the effects of maintaining the bone density and amount of calcium in the bone, reference maybe made to the invention described in JP 10-248525 A. However, this demonstrated no synergism with soybean isoflavone or genistein, one component thereof.
On the other hand, genistein is one of Leguminosae isoflavones and its action of increasing the bone mineral amount has been recently clarified. It has been clarified that genistein has an effect of inhibiting the function of osteoclasts that cause the lysis of bone mineral 10 times as potent as that of daidzein, which is also an isoflavone contained in soybean, etc. (Biol. Pharm. Bull., 22, 805-809, 1999). Further, it is known that genistein directly inhibits the bone resorption by osteoclasts in a culture system using a metaphysial tissue in the femora of old rats (Biochem. Pharmacol., 55: 71-76, 1998) and causes an increase in the amount of DNA, which serves as an index of an increase in bone mineral content and cell growth by osteoblasts (Res. Exp. Med. 197: 101-107, 1997). Furthermore, in 4-weeks old rats, its synergism with zinc on strengthening the bone has been observed (J. Bone Miner. Metab., 18: 77-83, 2000).
An object of the present invention is to provide a novel bone-strengthening agent, a bone-strengthening food composition and a bone-strengthening feed composition that prevent a decrease in bone density in association with the onset or progress of osteoporosis.
The inventors of the present invention have found out that not merely added-up effects but synergistic effects can also be achieved by the combined use of CPP, which is known as promoting the absorption of calcium essentially required for the soundness of bone and thus exerting an effect of strengthening bone, with genistein that directly acts on the bone tissue, inhibits bone resorption, and promotes osteogenesis, thus exerting an effect of strengthening bone. The present invention has been accomplished based on this finding.
Roughly divided, the present invention includes three types of aspects. That is, a first aspect relates to bone-strengthening agents; a second aspect relates to food compositions for strengthening bone; and a third aspect relates to feed compositions for strengthening bone.
A first aspect of the present invention relates to a bone-strengthening agent characterized by comprising casein phosphopeptide and genistein as active ingredients.
A second aspect of the present invention relates to a bone-strengthening food composition, characterized by comprising casein phosphopeptide and genistein as active ingredients.
A third aspect of the present invention relates to a bone-strengthening feed composition, characterized by comprising casein phosphopeptide and genistein as active ingredients.
Further, in the first to third aspects as described above, the present invention provides those that further contain a mineral in addition to casein phosphopeptide and genistein as active ingredients.
First, for the first aspect, there is provided the bone-strengthening agent described above, characterized by further comprising a mineral as an active ingredient.
Next, for the second aspect, there is provided the bone-strengthening food composition described above, characterized by further comprising a mineral as an active ingredient.
Further, for the third aspect, there is provided the bone-strengthening feed composition described above characterized by further comprising a mineral as an active ingredient.
Furthermore, in the first to third aspects as described above, the present invention provides those in which the above-mentioned mineral is at least one selected from calcium, magnesium and phosphorus.
First, for the first aspect, there is provided the bone-strengthening agent described above and further comprising a mineral, characterized in that the mineral is at least one selected from calcium, magnesium and phosphorus.
Next, for the second aspect, there is provided the bone-strengthening food composition described above and further comprising a mineral, characterized in that the mineral is at least one selected from calcium, magnesium and phosphorus.
Further, for the third aspect, there is provided the bone-strengthening feed composition described above and further comprising a mineral, characterized in that the mineral is at least one selected from calcium, magnesium and phosphorus.